Do I need lowering trailing arm cross member?

[64chevmn]

Hey guys; i tried to search and get a strong answer either way, but no luck so i'm looking for some opinions. I'm working on a 1968 C10 short box and doing a static 4/5 drop with lowering springs, drop spindles and shock relocate brackets. So, do you think i need to swap out my trailing arm cross member with a new lowering style to allow more room for the driveshaft and pinion angle? And if i don't need it for a 4/5 drop what about a 5/6 drop? I probably don't need to, but i'm also leaning towards a c-notch.